Field of Invention
The present invention relates to the field of mechanical technology, to a tie down device, and particularly to a chain load binder.
Related Art
In logistics operations, cargo needs to be bound, in order to avoid being damaged or lost caused by the bumps or vibrations during the transportation. The chain load binder is such a device used to secure cargo.
As proposed by the applicant, in a prior art device, the chain load binder comprises a housing with an inner cavity. Inside the housing, there is a sprocket able to rotate and wound by a chain. This driving mechanism comprises a rotation handle, a worm, a worm gear and a guiding part. The rotation handle is axially fixed to the housing, the worm gear is connected to the sprocket and the worm is circumferentially fixed to the rotation handle. The guiding part is always embedded into the teeth of the worm when the worm detaches from or meshes with the worm gear.
In the use of the above mechanism of the hand-driven chain load binder, rotating the rotation handle drives the worm to move forward, under the pressure from the guiding part, and to mesh with the worm gear to output a tightening force, and hence tighten the chain to bind cargo. However, there is an issue in the mechanism of the chain load binder. The design purpose of the housing is to support the worm, the worm gear and the guiding part, and in order to achieve a fairly good support, the housing is generally made of metals. It is heavy and easy to impact on other parts and result in big vibrations during the service or transportation, which impacts on the normal working condition of the parts inside the tie down.